Input: max77693-haptic - drop redundant haptic->input_dev->dev.parent assignment

devm_input_allocate_device() already initializes
haptic->input_dev->dev.parent to the supplied parent device, so the
explicit assignment in max77693_haptic_probe() is redundant. Remove it.

Assisted-by: LLM
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>